chapter 24 - respiratory diseases

Upper and Lower

-Nose
-Pharynx (throat)
-Larynx (voice box)
-Middle ear
-Eustachian (auditory) tubes

-Trachea (wind pipe)
-Bronchial tubes
-Alveoli (air scacs making in lungs)
-Pleura (lung membrane)

-Ducts from sinuses and lacrimal apparatus empty into the nasal cavity
-Auditory tubes from the middle ear empty into the upper part of the throat

-Make up the lung tissue
-O2 and CO2 are exchanged between lungs and blood

-Double layered membrane
-Encloses the lungs

Epiglottis

-Hair in nasal pasages
-IgA antibodies in nasal secretions, mucus, tears
-Normal microbiota provides competitive exclusion
-Ciliary escalator
-Alveolar macrophages in lung tissue

Ciliary escalator

Alveolar macrophages

Pharyngitis

Laryngitis

Tonsilitis

Sinusitis

Epiglottitis

-Cutaneous test
-Rapid antigen test
-PCR
-Serological tests
-Blood test
-Agglutination test
-Culture selective media
-Cytopathic effects

Cutaneous test

Rapid antigen tests

PCR

Serological tests

Blood test

Agllutination test

Strep Throat

Streptococcus pyogenes

Gram Positive

-Local inflammation
-Fever
-Tonsilitis
-Enlarged lymph nodes
-Otitis Media

Ear ache

-M protein
-Streptokinase
-Steptolysins

-Attachment
-Resistant to phagocytosis

Extracellular enzyme that lyse fibrin clots

Toxins that are cytotoxic to tissue cells, RBCs, and leukocytes

Rapid antigen test
Antibiotics

Stroptococcus pyogenes strain that has a lysogen (produces a toxin)

-Red skin rash
-Fever
-Strawberry tounge (looses upper membrane)

-Same as strep throat
-Erythrogenic toxin (reddening)
-Only the lysogenized strain

Antibiotics (to prevent rheumatic fever)

Corynebacterium diptherium (pleomorphic)

Gram positive

-Sore throat
-Fever
-Malaise
-Swelling of the neck
-Tough gray membran eforms in throat

-Bacturium is not invasive
-Exotoxin interferes with protein synthesis
-Strain carrying lysogen
-Can be fatal if heat and kidneys are affected

DTaP vaccine (Diptheria toxoid vaccine - inactivated diptheria toxin)

-Steptococcus pneumoniae (most common)
-Haemophilus influenzae
-Moraxella Catarrhalis
-Streptococcus pyogenes

-Formation of pus behind the eardrum
-Inflammation
-Pain
-Fever

Common in early childhood (eustachian tubes are more horizontal)

Common cold

-More than 200
-Most common = Rhinovirus
-Coronavirus

-Sneezing, nasal secretions
-Congestion
-Usually no fever

Bronchitis/ bronchiolotis

Pneumonia

Whooping cough

Bordetella pertussis

Gram negative

Obligate aerobe

-Catarrhal stage
-Paroxysmal stage
-Convalescence stage

Initial stage resemblig a common cold

-Prolonged intense coughing, gasping for air (lasts 1-6 weeks)
-Bacteria attches to ciliated cells in trachea (interferes w escalator)
-Damage to ciliated cells of trachea (mucus accumulates)

May last for months

-Capsule
-Two toxins: tracheal cytotoxin and pertussis toxin

Damages ciliated cells (not endo/exo toxin)

Enters bloodstream associated with systemic signs and symptoms (exotoxin)

-DTaP (acellular pertussis) vaccine
-Booster
-Vaccine requirements for students

Mycobarcterium tuberculosis

Acid fast!

Obligate aerobe

-Host is usually unaware of infection
-Coughing, bloodstained sputum
-Weight loss
-Can be fatal

-Acquired by inhalation
-Mycolic acids (in cell wall) stimulate inflammation
-Organisms that reach the lungs are phagocytized by aveolar macrophages (destroy the bacteria)
-Some bacteria may survive (infection present without symptoms)

-Resistant to drying
-Resistant to digestion by phagocitic cells
-Prevents fusion w lysosome
-Replicates in phagocyte

90% of them are ingested by macrophages
10% survive (infection present w/o symptoms)

-more macrophages gather
-they form a layer called an early tubercle
-macrophages release cytokines that cause lung-dammaging inflamation

A walled off lesion

-Form a caseous center (low O2 = bacteria do not grow)
-Latent TB (dormant)
-Lesion becomes calcified

-Caseous center grows (forming air-filled cavity)
-Microbes can grow

Bacteria spills into bronchioles (spread to lungs, circulatory and lymphatic systems)

-Tuberculin skin test (purified protein derivitive introduced cutaneously -> T cells react)
-Rapid Blood test (better for vaccinated people)
-PCR test (higher specificity)

Current or previous infection or vaccination
Needs x-ray or CT exam

Minimum of 6 months of drug therapy (antibiotics) bc of slow growth and dormancy

BCG vaccine (best for young children, not really used in US)

Streptococcus pneumoniae

Pleurisy

-Pneumococcal (most common)
-H. influenzae
-Mycoplasmal
-Legionellosis

Gram positive

-High fever
-Breathing difficulty
-Chest pains
-Reddish lungs (dialated blood vessels)
-Sputum is rust colored

-Involves bronchi and alveoli
-Dense capsule (resistant to phagocytosis)

Agglutination test (recognizes capsule antigen)
Broad-spectrum antibiotic

2 vaccines:
-Covers 13 strains
-Covers all 23 strains

Haemophilus influenzae

Gram negative

Resemble those of pneumococcal pneumonia

-IgA proteases (cut off arms of IgAs)
-Antigenic variation of surface antigens

-Gram stain of sputum (different from pneumococcal)
-Special media for nutritional requirements

HiB vaccine (reduces by 99% in children)

Mycoplasma pneumoniae

Walking pneumonia (or primary atypical pneumonia)
Less severe symptoms, lasts longer (common in college)

-Mild but persistent respiratory symptoms (3+ weeks)
-Low-grade fever
-Cough
-Headache

Community-Acquired Respiratory Distress Syndrome toxin (CARDS toxin)

PCR test
Fried egg appearance of colonies on growth medium

Tetracycline (doesn't elimitate it comepletely)

Legionella pneumophila

Gram negative

Aerobic

-High fever
-Cough
-General pneumonia symptoms
-Potenially fatal

Can replivate within macrophages
Forms biofilms

-Culture of selective media
-Serological tests

Viral pneumonia

It is suspected if no other cause is determined and mycoplasmal pneumonia is ruled out

Corona viruses

-RSV
-Influenza (flu)

Respiratory Syncytial Virus

Infants (most common, 1% need hospitalization)
Can be life threatening in older adults

Natural acquired immunity is poor (will likely get it more than once but not as bad)

-Pneumonia in infants
-Coughing and wheezing for more than a week

-Serological tests for viruses and antibodies
-Causes cell fusion (syncytium) in cell culture

Influenzavirus

-8 RNA segments
-Protein capsid
-Outer lipid envelope

-Fever
-Chills
-Headache
-Muscle ache
-No intestinal symptoms (respiratory not stomach flu)
-less tahn 1% death

Glycoproteins on the surface of the envelope are spikes:
-HA spikes
-NA spikes

Hemagglutinin spikes
Recognize and attach to host cells

Neuraminidase spikes
Help the virus separate from the enfected cell after resplication and infection

4 - A,B,C,D

2 - A,B

1 - A

A(H1N1)
A(H3N2)

B(Victoria)
B(Yamagata)

Antigenic drift
Antigenic shift

Point mutation in genes encoding HA or NA spikes

Changes in the flu virus strain and seasonal epidemics

Genetic recombination (or reassortment of RNS fragments) between different viral strains infecting the same cell

Changes in HA and NA spikes giving rise to major changes in the virus strain
Can lead to pandemics

Avian (bird) flu
Swine flu
Human flu

One cell can be infected by two different flu viruses
Segmented RNA genome increases rates of genetic re-assortment
Leads to a completely new strain